Paleocene-Eocene Deposystems in the Gulf of Mexico: Petroleum System Implications
Richard H. Fillon1, Arthur S. Waterman2, and Paul N.
Lawless3
1 Earth Studies Group, New Orleans, LA
2 Paleo-Data,
Inc, New Orleans,
3 Dominion Exploration &Production, Inc, New Orleans,
LA
Synoptic sequence maps based on >200,000 chronostratigraphically
correlated wells and published data clarify the history of Paleocene-Eocene
deposystems in the Gulf of Mexico. Epeiric carbonates, continental margin banks,
and steep continental slopes dominate the Gulf at the end of the Mesozoic. Into
this environment Laramide uplift sheds large volumes of siliciclastic detritus,
initiating the Paleocene-Eocene depositional cycle (PEDC). Mapped accumulation
patterns reveal accommodation created by the calcareous to siliceous basin
transition and mobile salt. The PEDC supports expanded shelf margin depocenters
in southeastern Texas, thin slope aprons, and a robust Western Gulf Basin fan
system fed from southeastern Mexico. A fan is also active in the Central Basin,
suggesting sediment transport through southeastern Louisiana. Inclusions of
Eocene sediments in salt bodies within the Neogene salt canopy support PEDC salt
displacement. The PEDC ends with accelerated uplift of the Colorado Plateau and
development of the Rio Grande Rift as a topographic barrier starving East Texas
drainage systems and feeding the Missouri-Mississippi system. Reduced deposition
across the western basin in the late Eocene and strong Oligocene regression in
East Texas point to the decline and virtual cessation of continental margin
subsidence. Increased early Oligocene deposition in South Louisiana records the
initial eastward shift of the Gulf margin depocenter
to its Neogene location. A
combination of active shelf margin expansion early in the PEDC and subsequent
development of the Rio Grande Rift, suggested by analysis of our synoptic map
data, limits optimal reservoir development in the Western Gulf to the early
Eocene (ca. 55.2-47.7 Ma).
AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005